Self-sharpening mechanical pencil



Julie 8, 1954 J. P. KOHUT SELF-SHARPENING MECHANICAL PENCIL Filed July 1, 1952 I! V FIG- 1 g 3nventor JOSEPH P. KOHUT (Ittorneg Patented June 8, 1954 UNITED STATES PATENT OFFICE 9 Claims.

This invention concerns mechanical pencils of the type in which mechanism is provided for sharpening the pencil lead. Pencils of this type are particularly useful for mechanical draftsmen who require a sharply pointed pencil to do eifective drafting.

According to this invention a lead sharpening blade is incorporated within and as a part of the pencil assembly. A lead holder forming part of the pencil is movable relative to the pencil barrel so that the lead may be retracted into the pencil and sharpened, and then extended to the normal position for drafting, with a minimum of complication and effort.

Objects of the invention are to provide a lead sharpener within a pencil which will form a concentric conical point on the pencil lead, to provide a cavity within the pencil for containing pencil lead scrapings so that they may not spill upon drafting work, and to provide a feeding arrangement for the pencil lead which will not interfere with the operation of the lead sharpener.

For a clear understanding of the details of the invention, reference may be made to the accompanying drawings in connection with the following description. The figures of the drawings show a preferred embodiment of the invention but various modifications may be made to the particular structure shown without departing from the spirit or scope of the invention.

In the drawings wherein similar reference characters designate similar parts,

Fig. 1 is a longitudinal section through a pencil according to the invention.

Fig. 2 is a section on the line 22 of Fig. 1.

Fig. 2-11 is a section on the line 2-2 of Fig. 1 with the parts in diiferent positions of adjustment from those shown in Fig. 2.

Fig. 3 is a section on the line3-3 of Fig. l.

The pencil of the invention comprises a tubular barrel ID to which a hollow pointed part II is secured through a hollow, partly tapered extension l2, the latter being secured to the barrel by means of a bushing M which is screwed at one end into the barrel l0 and at its other end into the extension 12.

The upper part of the barrel hollow as shown contains a stem I6 to which a flange I1 is secured, the upper portion of the stem l6 having a slidable seal l8 thereon. The upper end of the stem projects beyond the top of the pencil as at 2B and this part may be knurled to facilitate rotating of the stem by hand and longitudinal movement of the stem within the barrel as will become apparent. The upper end of the barrel is capped as at 22, the cap being screwed into the barrel and having an opening 23 therein through which the stem passes. Preferably the stem has one or more projections 24 thereon which pass through slots 25 in the cap. By twisting the stem IE it may be drawn upwardly from the barrel, the pins 24 passing through the slots 25. When the stem is moved downwardly into the barrel, the pins pass through the slots, the stem may be turned slightly and the stem is then held downwardly in the barrel by engagement of the pins with the under surface of the cap 22. These elements comprise means to lock the holding and feeding means, the stem It, in operative position in the barrel H).

The portion of the stem l6 below the flange ll carries clutch jaws 21 for engagement with the pencil lead 28. A sleeve has tapered engagement with the clutch jaws to force them together and to grip the lead, this sleeve by being urged downwardly by a bushing 32 carrying a flange 33 at its upper end. A compression spring 34 acts between the flanges I! and 33 and serves to force the clutch jaws 21 inwardly to engage the pencil lead. Bushing i4 is provided with shoulders 36 and 38 so that when the stem is pressed downwardly compressing the spring 34, the ends of the elements 30 and 32 engage the shoulders 38 and 36 so that the jaws 21 are projected therebeyond and disengage from the lead so that the lead is projected downwardly for feeding purposes.

The general push-feed action briefly described is not a specific part of this invention but forms a convenient way for lead holding and feeding. Suitable screw feed devices may be substituted for the mechanism above described if desired.

A spring 40, precompressed to lesser degree than the spring 34, is disposed between the flange 33 and the top of the bushing [4, this spring serving to urge the stem and its associated parts upwardly to press the pins 24 against the inside of the barrel cap 22. It will be seen from the above described construction that the stem along with the lead holding and feeding elements may be jointly withdrawn upwardly when the pins 24 are released from the cap 22 so that the lead 28 may be retracted a considerable distance within the pencil, and also may be projected downwardly so that the point of the lead 28 projects beyond the pencil point H.

Within the lower end of the bushing M are a pair of drillings 42 which are parallel to and spaced from the axis of the bushing. Sharpening blade members 43 are provided, each of which comprise an edged blade 44, the edge of which able a lead held by said holding and feeding means to engage said sharpening element, said means being rotatable in one direction to engage the sharpening element when swung into the path of said lead with the lead and being rotatable in the other direction to rotate said lead to swing, through frictional engagement, said sharpening element from the path of said lead, said sharpening element comprising a slant-edged blade pivoted for swinging on a pivot whose axis is spaced from and parallel to the barrel axis.

4. A mechanical pencil and .lead sharpener comprising a tubular barrel, means movable within the barrel for holding and feeding a pencil lead through the pencil end, said means including a manually operable feeding device, a lead pointing and sharpening element movable disposed in said barrel for lateral swinging near the pencil point, said means being retractable within the barrel to enable a lead held by said holding and feeding means to engage said sharpening element, said means being rotatable in one direction to engage the sharpening element when swung into the path of said lead with the lead and being rotatable in the other direction to rotate said lead to swing, through frictional engagement, said sharpening element from the path of said lead, said sharpening element comprising a slant-edged blade pivoted for swinging on a pivot whose axis is spaced from and parallel to the barrel axis, and elastic means urging said blade edge toward intersection with the barrel axis.

5. A mechanical pencil and lead sharpener comprising a tubular barrel, means movable within the barrel for holding and feeding a pencil lead through the pencil end, said means including a manually operable feeding device, a lead pointing and sharpening element movably disposed in said barrel for lateral swinging near the pencil point, said means being retractable within the barrel to enable a lead held by said holding and feeding means to engage said sharpening element, said means being rotatable in one direction to engage the sharpening element when swung into the path of said lead with the lead and being rotatable in the other direction to rotate said lead to swing, through frictional engagement, said sharpening element from the path of said lead, said sharpening element comprising a slant-edged blade pivoted for swinging on a pivot whose axis is spaced from and parallel to the barrel axis, elastic means urging saidblade edge toward intersection with the barrel axis, said holding and feeding means being translatable to extend the pointed lead through the barrel point in an operative position, and means to lock said holding and feeding means in said operative position.

6. A mechanical pencil and lead sharpener comprising a tubular barrel, means movable within the barrel for holding feeding a pencil lead through the pencil end, said means including a manually operable feeding device, a lead pointing and sharpening element movably disposed in said barrel for lateral swinging near the pencil point, said means being retractable within the barrel to enable a lead held by said holding and feeding means to engage said sharpening element, said means being rotatable in one direction to engage the sharpening element when swung into the path of said lead with the lead and being rotatable in the other direction to rotate said lead to swing, through frictional engagement, said sharpening element from the path of said lead,

blade pivoted for swinging on a pivot whose axis ing a manually operable feeding device, a lead pointing and sharpening element .movably disposed in said barrel for lateral swinging near the pencil point, said means being retractable Within the barrel to enable a lead held by said holding and feeding means to engage said sharpening element, said means being rotatable in one direction to engage the sharpening element when swung into the path of said lead with the lead and being rotatable in the other direction to rotate said lead to swing, through frictional engagement, said sharpening element from the path of said lead, said sharpening element comprising a slant-edged blade pivoted for swinging on a pivot whose axis is spaced from and parallel to the barrel axis, elastic means urging said blade edge toward intersection with the barrel axis, said barrel having a hollow cavity therein for receiving and containing lead scrapings, and sealing means in said barrel between the sharpening element and the pencil end to prevent the inadvertent escape of such scrapings.

8. A pencil comprising a hollow barrel, a conical point at one end thereof, a bushing joining said barrel and point, said bushing having a pivot parallel to the barrel axis and spaced therefrom, a lead sharpening blade mounted on said pivot for swinging across the barrel axis and away from the barrel axis, a stop on said bushing limiting said bushing having a hole therethrough for lead passage, a lead holding and feeding assembly rotatable and reciprocable in said barrel, means on the end of said assembly protruding from said barrel for rotating and reciprocating the assembly in said barrel, and means to lock the assembly in operative position in said barrel, whereby said lead is-movable by said assembly between a position extending from the pencil point and a position engaging said sharpening blade, and said lead is rotatable in one direction to be sharpened by said blade and is rotatable in the other direction to swing the blade away from the barrel axis to allow lead projection past the blade through the pencil point.

said blade in assembled position on said bushing,

said bushing having a hole therethrough for lead passage, a lead holding and feeding assembly rotatable and reciprocable in said barrel, means on the end of said assembly protruding from said barrel for rotating and reciprocating the assembly in said barrel, and means to lock the assembly sloped edge and a pivot pin with which said pin 10 pivot comprising a bearing with which said pin is engaged, the pin having a cross-slot formed thereon, and said resilient means comprising a spring ring embraeing part of said bushing and engaging within the cross-slot of said pin.

References Cited in the file of this patent UNITED STATES PATENTS Nnrnber Country Date 2,512,208 Kuper June 20, 1950 FOREIGN PATENTS Number Country Date 122,754 Sweden Sept. 14, 1948 

